﻿using System;
using System.Security.Cryptography;
using System.Text;
namespace stwh_Common.DEncrypt
{
    /// <summary>
    /// DES加密/解密类。
    /// Copyright (C) Maticsoft
    /// </summary>
    public class DESEncrypt
    {
        public DESEncrypt()
        {
        }
        #region ========加密========
        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="Text">明文</param>
        /// <returns>密文</returns>
        public static string Encrypt(string Text)
        {
            return Encrypt(Text, "keyname");
        }

        /// <summary> 
        /// 加密数据 
        /// </summary> 
        /// <param name="Text">明文</param> 
        /// <param name="sKey">密匙</param> 
        /// <returns>密文</returns> 
        public static string Encrypt(string Text, string sKey)
        {
            try
            {
                if (!string.IsNullOrEmpty(Text))
                {
                    DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                    byte[] inputByteArray;
                    inputByteArray = Encoding.Default.GetBytes(Text);
                    des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
                    des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
                    System.IO.MemoryStream ms = new System.IO.MemoryStream();
                    CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
                    cs.Write(inputByteArray, 0, inputByteArray.Length);
                    cs.FlushFinalBlock();
                    StringBuilder ret = new StringBuilder();
                    foreach (byte b in ms.ToArray())
                    {
                        ret.AppendFormat("{0:X2}", b);
                    }
                    return ret.ToString();
                }
                return Text;
            }
            catch (Exception)
            {
                return Text;
            }
        }
        #endregion
        #region ========解密========
        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="Text">密文</param>
        /// <returns>明文</returns>
        public static string Decrypt(string Text)
        {
            return Decrypt(Text, "keyname");
        }
        /// <summary> 
        /// 解密数据 
        /// </summary> 
        /// <param name="Text">密文</param> 
        /// <param name="sKey">密匙</param> 
        /// <returns>明文</returns> 
        public static string Decrypt(string Text, string sKey)
        {
            try
            {
                if (!string.IsNullOrEmpty(Text))
                {
                    DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                    int len;
                    len = Text.Length / 2;
                    byte[] inputByteArray = new byte[len];
                    int x, i;
                    for (x = 0; x < len; x++)
                    {
                        i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);
                        inputByteArray[x] = (byte)i;
                    }
                    des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
                    des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
                    System.IO.MemoryStream ms = new System.IO.MemoryStream();
                    CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
                    cs.Write(inputByteArray, 0, inputByteArray.Length);
                    cs.FlushFinalBlock();
                    return Encoding.Default.GetString(ms.ToArray());
                }
                return Text;
            }
            catch (Exception)
            {
                return Text;
            }
        }
        #endregion
    }
}
